The last word

I've just had my appendix removed. My surgeon told me I wouldn't miss it because it no longer serves a purpose in humans. But does it serve a purpose in some animals? What exactly?

• The equivalent of the true appendix in most animals is known as the caecum, which is at the junction of the small and large intestines. In general, carnivorous mammals have a small caecum that serves the same purpose as it does in humans. However, in many herbivorous mammals the caecum is greatly enlarged to create all sorts of wonderful anatomical arrangements. The function of the caecum in these mammals is to ferment the complex carbohydrates from the herbivorous diet into volatile fatty acids and then to absorb these as a source of energy. A functioning caecum is also vital for providing the energy needs of hindgut fermenters like horses, rabbits, rats, guinea pigs and swine. ...

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